You are correct. And that's exactly what I was attempting to do - relieve some pressure from the bones and distribute it around. Even as it is now, I feel like there is still too much pressure on the bones. Although the saddle is still hard as a rock, still no spongy or gel layer, except the old worn padding in my old cycling shorts. I took it for a 60km test ride once and I thought it performed fairly well. Still have to carve a deeper relief in the middle of the front.
Is there theory and practical evidence for minimizing soft tissue contact in bicycle saddles and forcing most of the pressure to the bones?
During summer I loaned out a demo split-nose saddle from a local bicycle shop. I noticed that the plastic base and the top were even flatter than my old Selle Italia saddle (which I ripped apart and used the base for this custom form saddle). Although I liked how the split-nose saddle relieved the center pressure from the crotch, the greater pressure on the bones got me sore very fast. It was worse than my old saddle. The old Selle Italia saddle base was angled down where the bones are, giving more room for the sponge layer. The split-nose was just about flat everywhere (actually all the split-nose saddles in the bike shop were like that). I did try sitting farther back or closer to front and it was just as bad.
All you need to do is a bit of searching online and you'll find a wealth of information on saddle design and why soft tissue contact should be minimized. Yes, sitting on bone will make you saddle sore until you get used to it, just as there is some level of discomfort associated with any form of exercise until your body adapts. Current saddle designs are the result of over a century of evolution; there's a reason they're shaped the way they are. There's also a reason why no major manufacturer of quality saddles tries to reduce sitz bone pressure by increasing pressure on soft tissue. If you think you're saddle sore now, just wait until you put in some miles sitting on mainly skin and muscle!
That said, there's a lot of physical variation between cyclists and the demands for different types of cycling affect saddle requirements, too, which is why there are so many saddle choices on the market. It took me several years and a lot of experimenting with saddles before I finally figured out what works for me, but you can shortcut that process somewhat. I suggest you find a good bike fitter who will measure your bone width to determine your ideal saddle width, assess your flexibility and discuss the type of riding you do. These days, bike shops often have saddle rental or test programs that allow you to try a few to determine what works best for you. Of course, you can experiment all you want, but your current approach will most likely fail miserably and waste a fair amount of time, compared to getting help from a professional.
I always question designs and look for ways to improve things, so I understand your desire to "build a better mousetrap".
I'm currently using a couple of different saddles. On my road bikes, I use E3 saddles (now sold as Kontact), but I modify them by adding a pressure relief groove and slightly reshaping the corners of the shell. This saddle works for me, but it may not be ideal for you. Prior to that, I was riding Fizik Pave saddles which I also modified by adding a groove. For off-road riding, I use Tri/TT-style saddles (the Forte T1 that was sold by Performance/Nashbar) with a cutout and padded nose. The keys to both designs being comfortable for me are that they're narrow and have an abrupt transition from the nose to the back, which is flat. I find I'm less sensitive to saddle design off-road, probably because I do fewer miles and spend a lot of time bouncing around and standing, rather than just sitting and grinding out road miles. I definitely prefer the narrower nose of the E3/Kontact for road riding.